1. Field of the Invention
The present invention generally relates to the field of assemblies for linking, or coupling, one or more devices. More specifically, embodiments of the present invention pertain to apparatuses for coupling fuel valves, air valves, damper assemblies, actuator motors, and/or the like in burner jackshaft assemblies.
2. Background and Description of Related Art
Conventional burner assemblies include linkage rods coupling a fuel valve and an air intake or inlet damper to maintain a nearly constant fuel/air ratio. Referring to the illustration of FIG. 1, a conventional burner assembly can include an air intake 26 and an actuator motor 20. In some implementations, actuator motor 20 can cooperate directly with the fuel valve. In other implementations, actuator motor 20 can be linked directly to the fuel valve much in the same way that actuator motor 20 is linked to air intake 26. In yet other implementations, a combination of linkages may be connected to a damper of an air intake, a fuel valve, and/or an actuator motor to accomplish and maintain proper air/fuel ratios.
Slotted bar 22 can be attached to a drive shaft of actuator motor 20 (or, in some implementations, a fuel valve). Similarly, slotted bar 28 can be attached to an air inlet damper of air intake 26. In some implementations, linkage rod 10 may couple slotted bar 22 and slotted bar 28. It is to be appreciated that as the drive shaft of actuator motor 20 moves, force may be transmitted through slotted bar 22, through linkage rod 10, to slotted bar 28. Thus, the opening of the gas valve can be proportional to the opening of the air inlet damper. Thus, actuator motor 20 may increase or decrease the amount of fuel to the burner assembly to provide more or less combustion while maintaining a relatively consistent air/fuel ratio.
It is to be appreciated that the air/fuel ratio of the burner is determined by the positioning of slotted bar 22 and slotted bar 28 on linkage rod 10, including among other things, the distance along linkage rod 10 between the coupling locations of slotted bar 22 and slotted bar 28 and the position of coupling location on slotted bar 22 and slotted bar 28. As such, when it is desired to change the air/fuel ratio of the burner, one or both of the coupling positions require adjustment.
Referring to the illustration of FIG. 2, some conventional applications include a solid linkage rod 10 and a coupling apparatus for securing linkage rod 10 to slotted bar 28. In some implementations, the conventional coupling apparatus can include a body 21 and a locking bolt 22. Forward rotation of locking bolt 22 within body 21 causes a distal end of locking bolt to come into frictional contact with linkage rod 10. Second bolt 24 can be provided with securing features (such as a hex nut) for removable engagement with, and positioning along, slotted bar 28. In some conventional applications, hinge joint 23 may be provided to enable movement of bolt 24 with respect to body 21.
In some applications, it is desirable to make adjustments to the air/fuel ratio while the burner is in operation. To do so, an operator must loosen bolt 22, slide body 21 along linkage rod to a desired position, and retighten bolt 22. In addition, an operator may also loosen the locking feature on bolt 24, slide bolt 24 along the slot of slotted bar 28, and retighten the locking feature on bolt 24. Once the adjustment has been made, the operator must analyze the new air/fuel ratio and make additional adjustments if necessary. Nonetheless, with conventional linkage assemblies, adjustments to the linkage while the burner is in operation is not recommended because of increased risk of explosion. It can be appreciated that after locking bolt 22 has been loosened, accidental slippage of linkage rod 10 through body 21 may occur, which may cause the air inlet damper attached to slotted bar 28 to completely or near completely close restricting air flow to the burner. Thus in many applications, it is necessary to turn off the burner before adjustments to the position of body 21 along linkage rod 10 can be made. After the adjustment is made and the burner is turned back on, a flue gas analysis can be made to determine whether additional adjustments need to be made.
It is to be appreciated that body 21 is secured in its position along linkage rod 10 by the frictional contact of locking bolt 22. In some instances, over tightening of locking bolt 22 causes permanent divots in linkage rod 10. Depending on the number of times that locking bolt 22 has been secured against linkage rod 10, and the tightening practices of the operator, the ability to make future fine-tuning adjustments may be reduced. For example, very small changes in the position of body 21 along linkage rod 10 may not be possible because bolt 22, when tightened, may slip into a divot previously formed in linkage rod 10. In addition, slippage of body 10 along linkage rod 10 may occur over time due to natural loosening of bolt 22. These and other inherent problems with conventional coupling apparatus require the linkage rod and/or the coupling apparatus to be replaced from time to time, increasing the down time of burner operations and increasing maintenance costs.
It is therefore desirable to provide coupling apparatuses which enable fine-tune adjustments to the positioning along a linkage rod and which obviate conventional wear and tear.